1. Field of the Invention
The present invention relates to compositions that include a component that is a product of materials comprising an amine and an anhydride and/or an anhydride derivative. Coating compositions of the invention are particularly useful as an underlying antireflective coating composition (“ARC”) employed with an overcoated photoresist layer in the manufacture of microelectronic wafers and other electronic devices.
2. Background
Photoresists are photosensitive films used for the transfer of images to a substrate. A coating layer of a photoresist is formed on a substrate and the photoresist layer is then exposed through a photomask to a source of activating radiation. The photomask has areas that are opaque to activating radiation and other areas that are transparent to activating radiation. Exposure to activating radiation provides a photoinduced or chemical transformation of the photoresist coating to thereby transfer the pattern of the photomask to the photoresist-coated substrate. Following exposure, the photoresist is developed to provide a relief image that permits selective processing of a substrate.
A photoresist can be either positive-acting or negative-acting. For most negative-acting photoresists, those coating layer portions that are exposed to activating radiation polymerize or crosslink in a reaction between a photoactive compound and polymerizable reagents of the photoresist composition. Consequently, the exposed coating portions are rendered less soluble in a developer solution than unexposed portions. For a positive-acting photoresist, exposed portions are rendered more soluble in a developer solution while areas not exposed remain comparatively less soluble in the developer solution. Photoresist compositions are described in Deforest, Photoresist Materials and Processes, McGraw Hill Book Company, New York, ch. 2, 1975 and by Moreau, Semiconductor Lithography, Principles, Practices and Materials, Plenum Press, New York, ch. 2 and 4.
A major use of photoresists is in semiconductor manufacture where an object is to convert a highly polished semiconductor slice, such as silicon or gallium arsenide, into a complex matrix of electron conducting paths, preferably of micron or submicron geometry, that perform circuit functions. Proper photoresist processing is a key to attaining this object. While there is a strong interdependency among the various photoresist processing steps, exposure is believed to be one of the most important steps in attaining high resolution photoresist images.
Reflection of activating radiation used to expose a photoresist often poses limits on resolution of the image patterned in the photoresist layer. Reflection of radiation from the substrate/photoresist interface can produce spatial variations in the radiation intensity in the photoresist, resulting in non-uniform photoresist linewidth upon development. Radiation also can scatter from the substrate/photoresist interface into regions of the photoresist where exposure is not intended, again resulting in linewidth variations. The amount of scattering and reflection will typically vary from region to region, resulting in further linewidth non-uniformity. Variations in substrate topography also can give rise to resolution-limiting problems.
One approach used to reduce the problem of reflected radiation has been the use of a radiation absorbing layer interposed between the substrate surface and the photoresist coating layer. See for example, PCT Application WO 90/03598, EPO Application No. 0 639 941 A1 and U.S. Pat. Nos. 4,910,122, 4,370,405, 4,362,809, and 5,939,236. Such layers have also been referred to as antireflective layers or antireflective compositions. See also U.S. Pat. Nos. 6,602,652; 6,528,235; 6,316,165; 6,190,839; 5,939,236; 5,886,102; 5,851,738; and 5,851,730, all assigned to the Shipley Company, which disclose highly useful antireflective compositions.
While current organic antireflective coating compositions are highly effective for many applications, it is also frequently desired to have particular antireflective compositions to meet specific processing requirements. For instance, it may be desired to remove a crosslinked antireflective layer that has been bared of overcoated photoresist (e.g. with a positive resist, exposed resist areas removed by alkaline aqueous developer) by means other than a plasma etchant. See U.S. Pat. No. 5,635,333; U.S. Patent Publication 2003/0166828; and U.S. Patent Publication 2003/0129531. Such approaches offer the potential of avoiding the additional processing steps and pitfalls associated with plasma etchant removal of a bottom antireflective coating layer. See U.S. Patent Publication 2003/0032298, which reports an attempt to address problems with plasma etching.
It would be desirable new compositions that could be used as underlying antireflective coating layer in the manufacture of microelectronic wafers. It would be particularly desirable to have new compositions that could be used as underlying antireflective coating layer and could be removed with an aqueous photoresist developer.